RESUMO
Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a rare adverse cutaneous reaction with a low incidence and high mortality. Despite posing a serious threat to patients' health and lives, there is no high-quality evidence for a standard treatment regimen. Here we report the case of a 62-year-old man with stage IV pancreatic cancer who experienced immunotherapy-induced SJS/TEN. After consensus-based regular treatments at a local hospital, his symptoms became worse. Thus, he consented to receive Chinese herbal medicine (CHM) therapy. The affected parts of the patient were treated with the CHM Pi-Yan-Ning which was applied externally for 20 min twice a day. After 7 days of treatment, the dead skin began peeling away from the former lesions that had covered his hands, feet, and lips, indicating that skin had regenerated. After 12 days of treatment, the patient's skin was completely recovered. In this case, SJS/TEN was successfully treated with Pi-Yan-Ning, suggesting that there might be tremendous potential for the use of Pi-Yan-Ning in the treatment of severe skin reactions to drug treatments. Further basic investigations and clinical trials to explore the mechanism and efficacy are needed.
Assuntos
Medicamentos de Ervas Chinesas , Síndrome de Stevens-Johnson , Medicamentos de Ervas Chinesas/uso terapêutico , Humanos , Fatores Imunológicos , Incidência , Masculino , Pessoa de Meia-Idade , Pele , Síndrome de Stevens-Johnson/tratamento farmacológico , Síndrome de Stevens-Johnson/etiologiaRESUMO
BACKGROUND: Lung cancer is the leading cause of cancer death. Platelet-related indictors, including platelet count, plateletcrit, mean platelet volume, and platelet distribution width, not only associate with morphology and functions of platelet but also correlate with tumor development and metastasis. In the present study, we investigated the values of platelet-related indictors in the prognosis evaluation of resectable lung cancers. METHODS: In total, 101 patients with resectable lung cancer were recruited in this study. Patients were divided into 2 groups according to the median pretreatment values. To evaluate the individual value changes after treatment, we introduced the concept of post-/pretreatment ratio (≤1 indicated value was not increased after treatment, while >1 suggested increased value). RESULTS: The high pretreatment platelet count level was correlated with larger tumor size. High pretreatment plateletcrit level was associated with more lymph nodes metastasis. Patients with high pretreatment plateletcrit level had worse overall survival, whereas pretreatment platelet count, mean platelet volume, and platelet distribution width levels were not correlated with outcomes. Surgery had no impact on the values of platelet count, plateletcrit, mean platelet volume, or platelet distribution width. Adjuvant chemotherapy significantly decreased the values of platelet count and plateletcrit, whereas it had no effect on the values of mean platelet volume or platelet distribution width. Whole course of treatment (surgery combined with adjuvant chemotherapy) significantly decreased the values of platelet count and platelet distribution width, whereas it had no effect on the values of plateletcrit or mean platelet volume. Post-/pretreatment platelet count, plateletcrit, mean platelet volume, and platelet distribution width ratios were not correlated with outcomes. Univariate analyses demonstrated that American Joint Committee on Cancer stage and pretreatment plateletcrit level were significant risk factors for prognosis. Cox regression analysis revealed that no factor independently associated with worse survival. CONCLUSION: Pretreatment plateletcrit level could be a potential prognostic factor in resectable lung cancers.
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Plaquetas/patologia , Carcinoma Pulmonar de Células não Pequenas/secundário , Neoplasias Pulmonares/patologia , Carcinoma de Pequenas Células do Pulmão/secundário , Plaquetas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/cirurgia , Metástase Linfática , Masculino , Volume Plaquetário Médio , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Estudos Retrospectivos , Carcinoma de Pequenas Células do Pulmão/metabolismo , Carcinoma de Pequenas Células do Pulmão/cirurgia , Taxa de SobrevidaRESUMO
The count and classification of white blood cells (WBCs) may be used as prognostic markers in certain types of cancer. The present study investigated the prognostic potential of the counts of WBCs, including lymphocytes (LYs), monocytes (MOs), neutrophils (NEs), eosinophils (EOs) and basophils (BAs), in the prognosis of resectable colorectal cancer. The present study recruited 153 resectable colorectal cancer cases retrospectively, which were pathologically confirmed. All patients were divided into two groups, according to the median value of LY (low LY, ≤1.632x109/l or high LY, >1.632x109/l), MO (low MO, ≤0.330x109/l or high MO, >0.330x109/l), NE (low NE, ≤3.600x109/l or high NE, >3.600x109/l), EO (low EO, ≤0.085x109/l or high EO, >0.085x109/l), BA (low BA, ≤0.010x109/l or high BA, >0.010x109/l), or WBC (low WBC, ≤5.780x109/l or high WBC, >5.780x109/l). To evaluate the alterations in WBC counts following surgery and adjuvant chemotherapy; all samples received oxiplatin and capecitabine (XELOX) for 68 cycles or 5fluorouracil, leucovorin and oxaliplatin (mFOLFOX6) for 1012 cycles. XELOX included oxaliplatin administered intravenously at a dose of 130 mg/m2 on day 1 and 8501,250 mg/m2 capecitabine twice daily for days 114, repeated every 3 weeks. mFOLFOX6 included oxaliplatin administered intravenously at a dose of 85 mg/m2, 400 mg/m2 leucovorin and 400 mg/m2 5FU on day 1 followed by 1,200 mg/m2/days continuous infusion for 2 days (in total, 2,400 mg/m2 over 4648 h), repeated every 2 weeks. The present study investigated the post/pretreatment of LY, MO, NE, EO, BA and WBC ratios (≤1 indicated that LY, MO, NE, EO, BA and WBC counts were not increased following therapy; whereas, >1 suggested increased counts). KaplanMeier curves were constructed to demonstrate overall survival (OS). A multivariate and univariate logistic regression analyses model was employed to identify the independent risk factors. Low pretreatment BA counts were associated with larger tumor size (>5 cm); pretreatment BA levels were positively associated with OS. Surgery significantly decreased the count of BAs and increased the count of EOs; whereas, no effect was observed on LYs, MOs, NEs or WBCs. Adjuvant chemotherapy markedly decreased the counts of LY, NE and WBC; whereas, no notable effects on MOs, EOs or BAs were observed. Whole course treatment (surgery combined with adjuvant chemotherapy) significantly decreased the values of LY, NE and WBC; however, increased the value of EO; no effects on the MO or BA counts were observed. An increased post/pretreatment NE ratio suggested poorer prognosis. Multivariate Cox regression analysis revealed that sex, tumor size, pretreatment BA count and the post/pretreatment NE ratio were independent prognostic factors affecting OS. The results of the present study suggested that the pretreatment BA count and post/pretreatment NE ratio may be potential prognostic factors for resectable colorectal cancer.
Assuntos
Neoplasias Colorretais/sangue , Neoplasias Colorretais/tratamento farmacológico , Contagem de Leucócitos , Prognóstico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Basófilos/efeitos dos fármacos , Capecitabina , Quimioterapia Adjuvante , Neoplasias Colorretais/patologia , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Eosinófilos/efeitos dos fármacos , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/análogos & derivados , Humanos , Leucovorina/administração & dosagem , Linfócitos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Neutrófilos/efeitos dos fármacos , Compostos Organoplatínicos/administração & dosagem , OxaloacetatosRESUMO
Cantharidin, one of the active components of mylabris, is believed to have antitumor activity. Cantharidin selectively inhibits protein phosphatase 2A (PP2A), which can repress multiple oncogenic kinases (ERK, JNK, PKC, and NF-κB). Researches in vitro have shown that cantharidin suppresses cell viability and metastasis in pancreatic cancer cells. This study aims to investigate the effects of cantharidin on pancreatic cancer xenografts in vivo. Xenograft models were established using cells stably expressing luciferase. Xenograft growth was evaluated by living imaging. Gene expression was determined using a microarray, real-time PCR, a RayBiotech antibody array, and the Milliplex assay. Surprisingly, cantharidin significantly accelerated xenograft growth. Living imaging showed a rapid distribution of D-luciferin in cantharidin-treated xenografts, suggesting a rich blood supply. Immunohistochemistry confirmed increased angiogenesis. Microarray and antibody array identified upregulated proangiogenic and downregulated antiangiogenic factors. The Milliplex assay suggested elevated secretion of IL-6, IL-8, TNF-α, and VEGF. Inhibitors of ERK, JNK, PKC, and NF-κB pathway attenuated the cantharidin-induced changes to proangiogenic gene expression. PKC pathway-inhibiting tamoxifen or antiangiogenic therapeutics, including Ginsenoside Rg3, bevacizumab, Apatinib, and Endostar, antagonized the proangiogenic effect of cantharidin or its derivatives. These regimens presented remarkable additive antitumor effects in vivo. Although cantharidin presents antitumor effects in vitro and has been applied in clinical practice, we revealed an unfavorable proangiogenic side effect. We recommend that the clinical application of cantharidin should be performed on the premise of antivascularization therapy.
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BACKGROUND: The classifications and counts of white blood cells (WBCs) have been proved to be able to be used as prognostic markers in cancer cases. The present study investigated the potential values of the classifications and counts of WBC, including lymphocyte (LY), monocyte (MO), neutrophil (NE), eosinophil (EO), and basophil (BA) in the prognosis of resectable gastric cancers (GCs). METHODS: This retrospective study recruited 104 resectable GC cases which were pathologically confirmed. The patients were divided into two groups according to the median pre-treatment values. To evaluate the changes in WBC counts and classification after treatment, we introduced the concept of post/pre-treatment ratios (≤ 1 indicated count was not increased after therapy, while > 1 suggested increased count). RESULTS: Pre-treatment NE and total WBC counts were negatively correlated with overall survival (OS). Surgery significantly decreased the level of NE count, but increased the level of EO, whereas had no effect on the levels of LY, MO, BAor total WBC. Adjuvant chemotherapy significantly decreased the level of BA. Whole course of treatment (surgery combined with adjuvant chemotherapy) had no significant effect on the counts of LY, MO, NE, EO, BA or total WBC. Post/pre-treatment ratios of LY, MO NE, EO, BA and total WBC levels had no effects on OS. Univariate analysis indicated that AJCC stage (III) and higher level of pre-treatment total WBC count were prognostic factors affecting OS. Multivariate Cox regression analysis revealed that AJCC stage (III) and higher level of pre-treatment total WBC count were independent prognostic factors. CONCLUSIONS: Pre-treatment NE count and pre-treatment total WBC count may be potential prognostic factors for the prognostic evaluation of GCs.
Assuntos
Neoplasias Gástricas/classificação , Neoplasias Gástricas/imunologia , Adulto , Idoso , Quimioterapia Adjuvante , Feminino , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Análise de SobrevidaRESUMO
PURPOSE: Despite new developments in cancer therapy, chemotherapy and radiotherapy remain the cornerstone of breast cancer treatment. Therefore, finding ways to reduce the toxicity and increase sensitivity is particularly important. Tumor necrosis factor alpha (TNF-α) exerts multiple functions in cell proliferation, differentiation and apoptosis. In the present study, we investigated whether TNF-α could enhance the effect of chemotherapy and radiotherapy against breast cancer cells. METHODS: Cell growth was determined by MTT assay in vitro, and by using nude mouse tumor xenograft model in vivo. Cell cycle and apoptosis/necrosis were evaluated by flow cytometry. DNA damage was visualized by phospho-Histone H2A.X staining. mRNA expression was assessed by using real-time PCR. Protein expression was tested by Western blot assay. RESULTS: TNF-α strengthened the cytotoxicity of docetaxel, 5-FU and cisplatin against breast cancer cells both in vitro and in vivo. TNF-α activated NF-κB pathway and dependently up-regulated expressions of CyclinD1, CyclinD2, CyclinE, CDK2, CDK4 and CDK6, the key regulators participating in G1âS phase transition. As a result, TNF-α drove cells out of quiescent G0/G1 phase, entering vulnerable proliferating phases. Treatment of TNF-α brought more DNA damage after Cs137-irradiation and strengthened G2/M and S phase cell cycle arrest induced by docetaxel and cisplatin respectively. Moreover, the up-regulation of RIP3 (a necroptosis marker) by 5-FU, and the activation of RIP3 by TNF-α, synergistically triggered necroptosis (programmed necrosis). Knockdown of RIP3 attenuated the synergetic effect of TNF-α and 5-FU. CONCLUSION: TNF-α presented radiotherapy- and chemotherapy-sensitizing effects against breast cancer cells.
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Squamous cell carcinoma (SCC) of pancreas is a rare histotype of pancreatic ductal carcinoma which is distinct from pancreatic adenocarcinoma (AC). Although there are standard treatments for pancreatic AC, no precise therapies exist for pancreatic SCC. Here, we screened 1033 cases of pancreatic cancer and identified 2 cases of pure SCC, which were pathologically diagnosed on the basis of finding definite intercellular bridges and/or focal keratin peal formation in the tumor cells. Immunohistochemistry assay confirmed the positive expression of CK5/6 and p63 in pancreatic SCC. To verify the genomic characteristics of pancreatic SCC, we employed in-solution hybrid capture targeting 137 cancer-related genes accompanied by high throughput sequencing (HTS) to compare the different genetic variants in SCC and AC of pancreas. We compared the genetic alterations of known biomarkers of pancreatic adenocarcinoma in different pancreatic cancer tissues, and identified nine mutated genes in SCC of pancreas: C7orf70, DNHD1, KPRP, MDM4, MUC6, OR51Q1, PTPRD, TCF4, TET2, and nine genes (ABCB1, CSF1R, CYP2C18, FBXW7, ITPA, KIAA0748, SOD2, SULT1A2, ZNF142) that are mutated in pancreatic AC. This study may have taken one step forward on the discovery of potential biomarkers for the targeted treatment of SCC of the pancreas.
Assuntos
Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Neoplasias Pancreáticas/genética , Adenocarcinoma/diagnóstico , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/metabolismo , Diagnóstico Diferencial , Ontologia Genética , Humanos , Mutação INDEL , Imuno-Histoquímica , Queratina-5/metabolismo , Queratina-6/metabolismo , Mutação , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/metabolismo , Polimorfismo de Nucleotídeo Único , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismoRESUMO
Previous studies have indicated that inflammatory stimulation represses protein phosphatase 2A (PP2A), a well-known tumor suppressor. However, whether PP2A repression participates in pancreatic cancer progression has not been verified. We used lipopolysaccharide (LPS) and macrophage-conditioned medium (MCM) to establish in vitro inflammation models, and investigated whether inflammatory stimuli affect pancreatic cancer cell growth and invasion PP2A catalytic subunit (PP2Ac)-dependently. Via nude mouse models of orthotopic tumor xenografts and dibutyltin dichloride (DBTC)-induced chronic pancreatitis, we evaluated the effect of an inflammatory microenvironment on PP2Ac expression in vivo. We cloned the PP2Acα and PP2Acß isoform promoters to investigate the PP2Ac transcriptional regulation mechanisms. MCM accelerated pancreatic cancer cell growth; MCM and LPS promoted cell invasion. DBTC promoted xenograft growth and metastasis, induced tumor-associated macrophage infiltration, promoted angiogenesis, activated the nuclear factor-κB (NF-κB) pathway, and repressed PP2Ac expression. In vitro, LPS and MCM downregulated PP2Ac mRNA and protein. PP2Acα overexpression attenuated JNK, ERK, PKC, and IKK phosphorylation, and impaired LPS/MCM-stimulated cell invasion and MCM-promoted cell growth. LPS and MCM activated the NF-κB pathway in vitro. LPS and MCM induced IKK and IκB phosphorylation, leading to p65/RelA nuclear translocation and transcriptional activation. Overexpression of the dominant negative forms of IKKα attenuated LPS and MCM downregulation of PP2Ac, suggesting inflammatory stimuli repress PP2Ac expression NF-κB pathway-dependently. Luciferase reporter gene assay verified that LPS and MCM downregulated PP2Ac transcription through an NF-κB-dependent pathway. Our study presents a new mechanism in inflammation-driven cancer progression through NF-κB pathway-dependent PP2Ac repression.
Assuntos
Hidrolases de Éster Carboxílico/metabolismo , NF-kappa B/metabolismo , Animais , Hidrolases de Éster Carboxílico/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Quinase I-kappa B/metabolismo , Lipopolissacarídeos/toxicidade , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nitrilas/farmacologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Fosforilação/efeitos dos fármacos , Transdução de Sinais , Sulfonas/farmacologia , Transplante HeterólogoRESUMO
OBJECTIVE: Angiogenesis is a critical step of breast cancer metastasis. Oncogenic Ras promotes the remodeling of cancer microenviroment. Tumor-associated macrophages (TAMs) are a prominent inflammatory cell population emerging in the microenviroment and facilitating the angiogenesis and metastasis. In the present study, we tried to investigate the relationship between the expression of Ras and infiltration of TAM, both of which could further promote angiogenesis. METHODS: Expressions of Ras, CD68 and CD34 were assessed by immunohistochemistry. The infiltration of macrophages was evaluated by counting the number of CD68(+) cells. Vessel endothelial cells were defined as CD34(+) cells. Angiogenesis vascularity was defined by microvessel density (MVD) assay through counting the number of vessels per field counted in the area of highest vascular density. The Kaplan-Meier survival analysis was used to estimate the overall survival (OS). Macrophages were derived from monocytes in the presence of macrophage colony-stimulating-factor (MCSF). Breast cancer cells were treated with macrophage-conditioned medium (MCM) and tested the expressions of K-, H- and N-Ras by using realtime-PCR. RESULTS: Ras positive status was correlated with ER, PR and Her-2 positivity, larger tumour size and lymph node metastasis, as well as higher TNM stages. A higher number of CD68(+) cells was correlated with larger tumour size, higher TNM stages and Her-2 positivity. Both Ras positivity and infiltration of CD68(+) macrophages correlated with poor OS. The number of CD68(+) cells was positively correlated with the expression of Ras. Treatment with MCM did not up-regulate but repressed the expression of Ras. Both up-regulation of Ras and infiltration of TAMs correlated with increased MVD. CONCLUSION: Expression of Ras and infiltration of TAM were positively correlated, and both participated in angiogenesis. Elevated Ras could be responsible for the infiltration of TAM.
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Cantharidin is an active constituent of mylabris, a traditional Chinese therapeutic agent. Cantharidin is a potent and selective inhibitor of protein phosphatase 2A (PP2A). Cantharidin has been previously reported to efficiently repress the growth of pancreatic cancer cells. However, excessively activated protein kinase C (PKC) has been shown to improve cell survival following the adminstration of cantharidin. Tamoxifen is widely used in the treatment of estrogen receptor-positive breast cancer. In addition, an increasing number of studies have found that tamoxifen selectively inhibits PKC and represses growth in estrogen receptor-negative cancer cells. Administration of a combination of PKC inhibitor and PP2A inhibitors has been demonstrated to exert a synergistic anticancer effect. The proliferation of pancreatic cancer cells was analyzed by 3-(4,5-dimethyltiazol-2-yl]2, 5-diphenyltetrazo-lium bromide assay. The expression levels of ERα and ERß in various pancreatic cancer cell lines were determined by reverse transcription polymerase chain reaction. In addition, the protein levels of PKCα and phosphorylated PKCα in pancreatic cell lines were analyzed by western blot analysis. In the present study, tamoxifen was found to exert a cytotoxic effect against pancreatic cancer cells independent of the hormone receptor status. Tamoxifen repressed the phosphorylation of PKC, and amplified the anticancer effect induced by cantharidin and norcantharidin. The findings reveal a novel potential strategy against pancreatic cancer using co-treatment with tamoxifen plus cantharidin or cantharidin derivatives.
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Cantharidin is an active constituent of mylabris, a traditional Chinese medicine, and presents strong anticancer activity in various cell lines. Cantharidin is a potent and selective inhibitor of serine/threonine protein phosphatase 2A (PP2A). Our previous studies revealed the prospect of application of cantharidin, as well as other PP2A inhibitors, in the treatment of pancreatic cancer. However, the mechanisms involved in the anticancer effect of PP2A inhibitors have not been fully explored. The Wnt/ßcatenin pathway is involved in cell migration and proliferation and participates in the progression of pancreatic cancer. If ßcatenin is phosphorylated and degraded, the Wnt/ßcatenin pathway is blocked. PP2A dephosphorylates ßcatenin and keeps the Wnt/ßcatenin pathway active. In the present study, we found that PP2A inhibitor treatment induced phosphorylation and degradation of ßcatenin. The suppression on the migration and growth of PANC1 pancreatic cancer cells could be attenuated by pretreatment with FH535, a ßcatenin pathway inhibitor. Microarray showed that PP2A inhibitor treatment induced expression changes in 13 of 138 genes downstream of the ßcatenin pathway. Realtime PCR further confirmed that FH535 attenuated the expression changes induced by PP2A inhibitors in 6 of these 13 candidate genes. These 6 genes, VEGFB, Dkk3, KRT8, NRP1, Cacnalg and WISP2, have been confirmed to participate in the migration and/or growth regulation in previous studies. Thus, the phosphorylation- and degradation-mediated suppression on ßcatenin participates in the cytotoxicity of PP2A inhibitors. Our findings may provide insight into the treatment of pancreatic cancer using a targeting PP2A strategy.
Assuntos
Inibidores Enzimáticos/farmacologia , Neoplasias Pancreáticas/patologia , Proteína Fosfatase 2/antagonistas & inibidores , beta Catenina/metabolismo , Antracenos/farmacologia , Cantaridina/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Fosforilação , Sulfonamidas/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/genéticaRESUMO
We found that artesunate (ART) inhibited the growth of MCF-7 and MDA-MB-231 breast cancer cells. ART arrested the cell cycle in the G2/M phase, which was accompanied by an upregulation of p21. ART upregulated the expression of Beclin1, an initiator of autophagy (type II programmed cell death). In addition, ART stimulated the aggregation of LC3, which is considered to be a marker of autophagosome formation. We further verified the transformation of LC3 from type I into type II. 3-MA, a classical autophagy inhibitor, attenuated ART-induced autophagosome formation, cell growth repression, G2/M arrest, and p21 upregulation. Autophagy induction and p21 upregulation were also repressed by knockdown of Beclin1. Furthermore, ART sensitized breast cancer cells to the chemotherapeutic agent epirubicin through an autophagy-dependent cascade. Our study showed that ART induced autophagy in breast cancer cells and indicated that the anticancer effects of ART were exerted through an autophagy pathway. Moreover, ART sensitized breast cancer cells to epirubicin chemotherapy. Our results provide a basis for further development of ART as a novel therapeutic agent for the treatment of breast cancer.
Assuntos
Antineoplásicos/farmacologia , Artemisininas/farmacologia , Autofagia/efeitos dos fármacos , Neoplasias da Mama/patologia , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Artesunato , Proteína Beclina-1 , Linhagem Celular Tumoral , Sinergismo Farmacológico , Epirubicina/farmacologia , Feminino , Humanos , Proteínas de Membrana/metabolismoRESUMO
Cancer metastasis is a highly coordinated and dynamic multistep process in which cancer cells interact with a variety of host cells. Morphological studies have documented the association of circulating tumor cells with host platelets, where a surface coating of platelets protects tumor cells from mechanical trauma and the immune system. Cantharidin is an active constituent of mylabris, a traditional Chinese medicine. Cantharidin and norcantharidin are potent protein phosphatase 2A (PP2A) inhibitors that exhibit in vitro and in vivo antitumor activity against several types of cancer, including breast cancer. We investigated whether cantharidin and norcantharidin could repress the ability of MCF-7 breast cancer cells to adhere to platelets. Using MTT, clone formation, apoptosis, adhesion and wound-healing assays, we found that cantharidin and norcantharidin induced apoptosis and repressed MCF-7 cell growth, adhesion and migration. Moreover, we developed a flow cytometry-based analysis of tumor cell adhesion to platelets. We proved that cantharidin and norcantharidin repressed MCF-7 cell adhesion to platelets through downregulation of α2 integrin, an adhesion molecule present on the surface of cancer cells. The repression of α2 integrin expression was found to be executed through the protein kinase C pathway, the activation of which could have been due to PP2A inhibition.